| HCI # | Sizing | Inches | Centimeters |
| Kids Sizes | |||
| 02 | S | 20 1/4 | 52 |
| 03 | M | 21 | 54 |
| 04 | L | 21 3/4 | 56 |
| 05 | XL | 22 1/2 | 58 |
| HCI # | Sizing | Inches | Centimeters |
| Adult Sizes | |||
| 01 | XS | 20 1/4 - 20 7/8 | 52 - 53 |
| 02 | S | 21- 21 5/8 | 54 - 55 |
| 03 | M | 21 3/4 - 22 3/8 | 56 - 57 |
| 04 | L | 22 1/2 - 23 1/8 | 58 - 59 |
| 05 | XL | 23 1/4 - 24 | 60 - 61 |
| 06 | XXL | 24 1/8 - 24 7/8 | 62 - 63 |
| 07 | XXXL | 25 - 25 1/2 | 64 |
HCI helmet size chart
